Recently, in the field of electroluminescence, when an electroluminescent material is coated by ink-jetting, it is required to form a pixel defining layer in an electroluminescent device so as to define a coating region and prevent a solution of the electroluminescent material from flowing into an adjacent pixel.
As shown in FIG. 1 which is a sectional view of an existing electroluminescent device, FIG. 2 which is a top view of the existing electroluminescent device and FIG. 3 which is a schematic view showing an existing pixel defining layer, the electroluminescent device includes a substrate 1 and a pixel defining layer 2 arranged on the substrate 1. A pixel aperture matrix is formed in the pixel defining layer 2 and corresponds to a pixel unit matrix, i.e., each pixel unit 8 corresponds to a pixel aperture 4. An electroluminescent layer 3 in a predetermined color is formed in the pixel aperture 4. For example, an electroluminescent layer 7 in red is formed in the pixel aperture 4 corresponding to a red pixel unit, an electroluminescent layer 6 in green is formed in the pixel aperture 4 corresponding to a green pixel unit, and an electroluminescent layer 5 in blue is formed in the pixel aperture 4 corresponding to a blue pixel unit.
A procedure of forming the electroluminescent layer by ink-jetting will be described hereinafter by taking the electroluminescent layer 7 in red formed in the pixel aperture 4 corresponding to the red pixel unit as an example. At first, a solution of a red electroluminescent material is dripped by two (or more) nozzles of an inkjet device into the pixel aperture at a corresponding position, and after the dripping, the solution of red the electroluminescent material is dried by a drying device so as to form the electroluminescent layer 7 in red.
However, during the dripping of the solution of the red electroluminescent material, due to the possible difference in the amounts of the solution dripped by different nozzles, the amounts of the solution of the red electroluminescent material in different pixel apertures may be different from each other. As a result, the electroluminescent layers 7 in red formed after the drying process will have different thicknesses, i.e., the entire electroluminescent layer 7 in red in the electroluminescent device is of an uneven thickness.
In the related art, when the electroluminescent layers in an identical color in the electroluminescent device are of different thicknesses, uneven light beams may be generated by the electroluminescent device. As a result, such a phenomenon as Mura will occur and the performance of the electroluminescent device will be affected adversely.